Tuesday, August 4, 2015

I found this article on Mike Nelson’s KMGH-TV (Denver) blog last night. He is my long time friend and I thought he hit upon several good points. The climate debate (when allowed) is not black & white. Hope you enjoy this read?

By Mike Nelson, Chief Meteorologist KMGH-TV, News 7 Denver…

Climate change will likely be higher in the news conversation in the coming days, so here is some information from my perspective...

Over the course of time, I have been called many different things while talking and writing about this subject. From courageous to foolish, to (my favorite) "the Pied Piper of Anti-Science"!

The TV meteorologist is often asked to provide their viewers with insight and explanations on earthquakes, meteors and comets, tsunamis and volcanoes. For many Americans, we are as close to a scientist as they will get, and they invite us into their living rooms.

I hope that, even if you do not agree with my comments and explanations, you will appreciate the attempt and still choose to watch my weather reports. With that said, here we go...

Weather is NOT Climate!

It is important to understand that a heat-wave, tornado outbreak, record flood or major blizzard is not climate - it is weather! The weather goes through tremendous fluctuations from day to day and even hour to hour - let alone over the course of weeks, months or even years.

Scientists at the National Center for Atmospheric Research (NCAR) feel that 90 to 95% of what we see in the wide variety of weather is due to natural variability. The remaining 5 to 10% is due to the warming of the planet due to an increase in various greenhouse gases.

If 5 to 10% of the change does not seem like much, consider what that can mean in terms of tangible measurements. A 5 to 10% drop in crop yields in future decades would have a huge impact on agri-business in our state and across the nation.

A 5 to 10% drop in snowpack in future decades would be a major concern for Colorado and the West. A 5 to 10% increase in insurance losses from weather would amount to billions of dollars over the long term.

Even though an individual severe weather event cannot be blamed on Global Warming, a warmer climate "juices" the atmosphere and may bring more frequent severe weather events in the future.

One Cold Winter Does Not Mean There Is No Global Warming!

There are often comments and questions about Global Warming when unusual regional weather events occur - such as recent snow in Sidney, Australia or extremely cold weather this past winter in the eastern U.S. It is important to understand that short term weather is to climate as one play in a football game is to the entire history of the NFL.

For example, the extreme episodes of cold and snow in southern locales is due to a southern bulge in the circumpolar vortex, bringing the chilly air down from Alaska and Canada into the lower 48 states.

This past winter, while portions of the lower 48 states were shivering, Fairbanks had a warm and dry winter that has led to the numerous wildfires this summer in Alaska and western Canada.

The key here is that we are talking about regional weather events. Things tend to even out - if one area is unusually warm, another is cold. But on a global average, we are seeing a warming of the planet by about 1.5 degrees Fahrenheit since 1900.

The World Has Not Warmed Since 1997!

There is an often quoted issue of 1997 being the warmest year and that global temperatures have cooled since that time. This information is misleading. In 1997, the world climate was influenced by one of the strongest El Nino events ever recorded.

This pool of very warm Pacific Ocean water bumped global temperatures higher. Temperatures have remained warmer than the long term average in the years since 1997 - just not quite as warm as that one spike.

The oceans have an enormous capacity to absorb heat and much of the global warming we are seeing is going into the oceans. This is causing sea levels to rise and the increase in CO2 is changing the chemistry of the water – making it more acidic.

But in the 1970s, They Said The Earth Was Cooling!

I did my meteorology training at the University of Wisconsin at Madison in the 1970s. At that time, Dr. Reid Bryson, one of the founders of the UW Meteorology Department was lecturing about the prospect of a "New Ice Age". The cause, Bryson theorized, was due to the increase in tiny particles of smoke and dust during the Industrial Revolution.

The increase in atmospheric aerosols would block incoming sunlight like a dirty window. It was from that theory that several magazines ran feature articles about "Global Cooling". It stands to reason that folks would be concerned about such an about face in forty years.

In fact, even at the time, most researchers, including Bryson, felt that the increase in CO2 would eventually offset this "dirty window" effect and the climate would begin to warm. This is an important point, as many anthropogenic global warming (AGW) skeptics still bring up the "1970s Global Cooling Theory" as an argument that the current consensus among climate scientists has been an "about face" form the 1970s.

Here is an article about this from the Bulletin of the American Meteorological Society...

For nearly 150 years scientists have known that each doubling of the CO2 results in a net increase of 4 watts per square meter of stored energy over the entire surface of the Earth. That is about a night-light’s worth of heat over a square meter, but taken over the vast surface area of the Earth, this is a tremendous amount of energy!

Climate Has Always Changed

It is absolutely true that the Earth's climate has cycled through great changes over the course of our geologic history. These changes are obvious in the fossil record - Denver was once under a great shallow ocean!

These changes are due to a variety of causes, from volcanoes to continental drift to the shift in the Earth's orbit on its journey around the Sun, to changes in the output of energy from the Sun.

One of the key components to our Ice Ages has been what are called the Milankovitch Cycles. These long term changes in the shape of our orbit and the shift in the tilt of the Earth work like the complex gears of a clock, gradually switching our planet from Ice Age to warmer periods and back again.

The Milankovitch Cycles are well documented and have been a primary driver of our changing climate for hundreds of thousands to millions of years. Here is a link to learn more...

The topic of climate change has been given much political attention and in that light, there is a seemingly large controversy about what is happening and to what extent mankind is helping to cause some of the changes. In the strict world of truly peer reviewed science, the degree of controversy is not as great as some would have you believe.

The American Meteorological Society (AMS) is the oldest and largest professional society for weather and climate researchers. Here is a link to their statement on Climate Change.